To provide consistent, high-performance client support, many businesses rely on high-availability data storage systems. High-availability data storage systems are designed with a level of redundancy in order to provide fault tolerance for single points of failure. Two components that are typically replicated in high-availability designs are the storage processors and the power supply. In the event that one of the processors or the power supply fails, the back-up component of the redundant pair is utilized to continue the operation of the data storage system.
Such redundancy of the power sources in high-availability systems typically relies on full N+1 redundancy of all of the power supply outputs which are shared between all of the attached loads, such as the processors and disk drive arrays. However, the disadvantage of such redundancy is that the power system, when not redundant, must power the entire load. The N+1 redundancy arrangement requires N+1 times the power capacity from the power system than that which would be necessary to power a non-redundant system. The additional power requirements of the N+1 redundant system adds cost and complexity to the data storage system and increases the space requirements of the power supply system within the data storage system.